687620191 has 2 divisors, whose sum is σ = 687620192. Its totient is φ = 687620190.

The previous prime is 687620183. The next prime is 687620201. The reversal of 687620191 is 191026786.

687620191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 687620191 - 2³ = 687620183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687620491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343810095 + 343810096.

It is an arithmetic number, because the mean of its divisors is an integer number (343810096).

Almost surely, 2^687620191 is an apocalyptic number.

687620191 is a deficient number, since it is larger than the sum of its proper divisors (1).

687620191 is an equidigital number, since it uses as much as digits as its factorization.

687620191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 687620191 is about 26222.5130565322. The cubic root of 687620191 is about 882.6385130888.

The spelling of 687620191 in words is "six hundred eighty-seven million, six hundred twenty thousand, one hundred ninety-one".